Anorexia and Bulimia may be Caused by Altered Brain Pathways

A study from the University of California, San Diego School of Medicine has found a possible link between altered neural circuitry and anorexia and bulimia. The findings suggest that the altered wiring in the brain may contribute to the restrictive eating habits in people with eating disorders.

"It has been unknown whether individuals with anorexia or bulimia have a disturbance in the system that regulates appetite in the brain, or whether eating behaviour is driven by other phenomena, such as an obsessional preoccupation with body image," said Kaye, director of the UCSD Eating Disorders Treatment and Research Program. "However, this study confirms earlier studies by our group and others that establish a clear link between these disorders and neural processes in the insula, an area of the brain where taste is sensed and integrated with reward to help determine whether an individual hungry or full."

The study used MRI scanning to test 28 recovering anorexics and bulimics. Their results were measured against the test results of 14 women who have no history of eating disorders.

The testing found that, compared to the control group, anorexics showed lower neural responses to taste while bulimics showed substantially elevated responses.

"One possibility is that restricted eating and weight loss occurs in anorexia because the brain fails to accurately recognize hunger signals," said the study’s author, Tyson Oberndorfer. "Alternately, overeating in bulimia could represent an exaggerated perception of hunger signals."

These results mirror the results of previous testing which also found the region of the brain known as the insula could be somehow wired wrong in people with eating disorders.

"It may be possible to modulate the experience by, for example, enhancing insula activity in individuals with anorexia or dampening the exaggerated or unstable response to food in those with bulimia," said the study’s lead author, Walter Kaye.

The new study also helped to develop some possible treatments for eating disorders. For those suffering from anorexia, the research indicates that patients may benefits from eating bland or less palatable foods that will help prevent the brain from being overstimulated. The research also shows that there may be a way to produce medications to help people with eating disorders.